The sum of two numbers is 88. If four times the smaller number is subtracted from the larger number, the result is 13. Find the two numbers.

73 and 15

Step-by-step explanation:

I made two variables for this:

x = larger number

y = smaller number

Write an equation for "the sum of two number is 88" and you get:

x + y = 88

Write an equation for "four times the smaller number is subtracted from the larger number" and you get:

x - 4y = 13

I do not want an equation with both x and y in it, so I will rewrite the first one and use substitution in the second one:

x + y = 88   -- move the x to the other side

y = 88 - x

x - 4y = 13 -- substitute for y

x - 4(88 - x) = 13 -- multiply by 4

x - 352 + 4x = 13 -- move -352 to the other side, combine x's

5x = 365 -- divide by 5

x = 73

Now that I know x is 73, I go back to my first equation (x + y = 88) and I get:

73 + y = 88 -- subtract 73 from both sides

y = 88 - 73

y = 15